61903-RSR bearing: complete specifications & equivalents
The 61903-RSR is a ISO 15 radial bearing sized 17 x 30 x 7 mm (bore x OD x width) with RSR sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 17 mm |
| Outer diameter D | 30 mm |
| Width B | 7 mm |
| Material | GCr15 |
| Seal / shield | RSR |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 4.62 kN |
| Basic static load rating C0 | 2.55 kN |
| Fatigue load limit Pu | 0.108 kN |
| Reference speed (thermal) | 50000 rpm |
| Limiting speed (mechanical) | 26000 rpm |
| Operating temperature | -30 to +120 °C |
| Mass | 18 g |
| Manufacturer designation | SKF 61903-2RZ |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-24 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-24
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & 61900-series range
| Bore d | 0.669 in |
|---|---|
| Outer diameter D | 1.181 in |
| Width B | 0.276 in |
| ISO bore code | 03 |
| Radial section height (D−d)/2 | 6.5 mm |
| Smallest bore in 61900-series | 10 mm |
| Largest outer diameter in 61900-series | 420 mm |
| Width range across 61900-series | 6–56 mm |
| Bore position in 61900-series (smallest first) | 4 of 35 |
| Bore above smallest 61900-series size | 7 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61903 | ISO 15 | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range. Brand-specific OEM equivalents pending multi-source data. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 61903-RSR model number is decoded
In the 61900-series (ISO 15 diameter series 9) the last two digits encode the bore: 61903 carries bore code 03 = 17 mm. Codes 00–03 follow the 10/12/15/17 mm exception table rather than code × 5. Outside diameter 30 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 17 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude.
Typical equipment & failure modes
Common applications
- clutch and transmission assemblies
- robotics and automation joints
- lay shafts and idler shafts
- textile machinery
Known failure patterns
- ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)
- lip-lubricant starvation if the bearing runs dry for extended periods
- brinelling from static overload or hammering during mounting
- false brinelling from vibration while the shaft is stationary
Selection pitfalls — read before you substitute
- Bore codes 00–03 use the exception table: 61903 fits a 17 mm shaft — the code × 5 mnemonic does not apply below code 04 (it would imply 0 mm for code 00).
- The 619xx thin section (6.5 mm section height at 17 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
- RSR low-friction seals on 61903-RSR run faster than contact-seal 61903-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61903-2RS instead.
- The non-contact lip of 61903-RSR does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 17 mm bore position before relying on it as sealed-for-life.
- Deep-groove ball bearings tolerate only minutes of misalignment; if the 30 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61903-RSR.
- SKF catalogues the low-friction seal as 61903-2RZ (suffix -2RSL or -2RZ): a non-contact elastomer lip that runs near the open 26000 r/min limiting speed, closer to the open bearing's 50000 r/min reference than the contact-seal version. It keeps coarse debris out without the drag of a contact seal, but is not liquid-tight — use 2RSH for wet or fine-dust positions.
- The 4.62/2.55 kN ratings here are SKF Explorer-class figures from catalogue PUB BU/P1 17000/1 EN (Oct 2018); SKF can revise internal geometry and ratings without changing the designation, so treat the catalogue version and date as part of the specification and re-verify for critical drives.
Frequently asked questions
What are the dimensions of a 61903-RSR bearing?
A 61903-RSR deep-groove ball bearing has a 17 mm bore, 30 mm outer diameter and 7 mm width (0.669 × 1.181 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals.
Why does 61903 not follow the bore-code × 5 rule?
Codes 00–03 use the exception table (10, 12, 15 and 17 mm): 61903 with code 03 has a 17 mm bore. The code × 5 convention starts at code 04 (20 mm).
What does the RSR suffix on 61903-RSR mean?
RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments.
How does the 61900 compare with other series at the same 17 mm bore?
619 is a thin section one step above 618: 30×7 mm with a 6.5 mm radial section at 17 mm bore; a 6203 on the same bore is substantially larger and more heavily rated.
What is the SKF designation and catalogue data for 61903-RSR?
In the SKF Rolling Bearings catalogue this size is listed as 61903-2RZ — two low-friction non-contact elastomer seals, 17×30×7 mm per ISO 15. Quoted values: C 4.62 kN, C0 2.55 kN, Pu 0.108 kN, limiting speed 26000 r/min, mass 18 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61903-RSR.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-24. Read our editorial & correction policy.